Method of treating steel plates.



G. DAVIS. METHOD 0F TREATING STEEL PLATES.

APPLIOAYTION FILED Nov.1z. 1902. I 935,358, Patented Sept. 28, 1909.

@qu l tains to make and use the same.

CLELAND DAVIS, 0F THE UNITED STATES NAVY.

` Specification of Letters Patent.

imrnon or 'HEATING anni. PLATES.

Patented Sept. 28, 1909.

Application led November 12, 1902. Serial No. 131,025.

vTo all whom 'it may concern:

l Plates; land I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it apper- My present invention relates to improvements in the manufacture'of steel plate, and it consists in-an improved method'of incorporating into the face of the plate some other metal or metallic compound such as nickel, chromium, or the like, or alloys or compounds of the same,.or other elements or l compounds which maybe advantageously emp oyed. I

My invention is especially adapted to the manufacture of improved armor plate.

It is well known that the use of certain metallic elements, such as nickel and chrome in steel, impart to it ualities that increase its value for armor p ate. But conditions of manufacture, well known in the art, limit the employment of these metals, sothat it is not practicable with present methods to utilize them to the best advantage.

The object of my invention'is to incorporate these ingredients so that a portion only of the plate will be impregnated, at the same time maintainin the integral molecular character of the w ole.

The substance to be incorporated may be I laid on the face of the plate in a thin sheet,

or in the form of a granular mass, or may be inserted 'in pockets drilled, pressed, Vor cast into the plate, or in any other convenient Way. Then-the face of the plate is subjected to a temperature high enough to melt .both the face of the plate and the material to be incorporated, and the latter will become incorporated -or dissolved in the molten metal, thus alteringk the properties of that face of the plate. To prevent oxidation it -will ordinarily be preferable to exclude the air from the portion of the plate bein treated. This meltln of the face of the p ate, with the materia to be incor orated therein, is accomplished by means o an electric arc,y as will. be hereinafter described. Furthermore,

if4 it be desired to incorporate carbon into the metal or metallic com ound is to be incorporated, this may be one by using carbon electrodes. x

, The accompanying drawings illustrate diagrammatically the apparatus for putting my said invention into practice.

The same letters refer `to the same parts in the several views.

Figure 1 represents a transverse section through a plate provided with pockets for the material to be incorporated, and shows the electrodes in elevation and the casing in section. Fi 2 is a plan view of a part of the cover o the casing shown in Fig. 1, and shows the distribution of the electrodes, the conductors being omitted. Fig. 3 shows the apparatus for automatically feeding the electrodes, and Fi 4 shows a plate with the material to e incorporated resting thereon in the form of a fiat plate.

A represents the plate to be treated which, in the form shown in Fig. 1, is provided with pockets a for the material to be incorporated. In the form shown in Fig. 4.-, this material to be incorporated is in the form of a fiat plate A. The plate A rests on suitable rails, or other supports B, which are insulated as shown at B. The beams B2 and B3, and the cover D form a casing which cffectually screens the plate from air while it is being treated. The joints between the plate andthe sides D3 of the casing are stopped with asbestos or other refractory material als to prevent the escape of any of the molten metal from the top of theplate. The electrodes C are mounted in sultable holes C0 carried by the plate K, which is mounted .above the cover D. The current passes through these electrodes, and is carried ofi by the conductor E. Where carbon electrodes are used, it is desirable to have.

automatic devices for feeding the same toward the plate, and Fi 3 shows one well known apparatus for t is purpose, which comprises the springsl o0 connected to the magnetic holder C which moves up or vdown in the coils C2 as the current varies through the conductors N, N and N2. This automatic feed is not a part of my invention, and any other suitable device for the purpose may be adopted if desired.

stancato the surface portion o nated, carbon electrodes may be used, in which casefan automatic feed to adjust the length of the arc will be required.

Thel current may be turned 011 to all the electrodes at once if desired, or Yon groups of the electrodes, thus heating portions of the facel of vthe plate, and thus progressively treating the entire plate; or the plate maybe moved under the electrodes,'or the electrodes maybe moved over the face of the plate, as'l may be preferred.

' It will be obv1ous'that various modifications in the herein described apparatus may -be used, which could be used without de- Y pregnating the face of a steel plate with foreign matter, which consists in applying said matter tothe face of said plate, and thereafter melting the face of the plate and the matter by means of an electric arc, the face of the plate under treatment being in the meantime screened from air.

3. The herein described process of impregnating the face of a steel plate with other metallic substances, which consists in the said material and the steel along theface of .the plate by means of an electric arc, the

applfying the material to be incorporated to ace of the plate, and thereafter melting face of the plate under treatmentbeing in.

- the meantime screened from air.

f 4. The method of incorporating foreign matter intothe face of a steel plate and in simultaneously carburizing said face, which consists in applyinggthe said matter to the face of said plate, 'thereafter melting said face and said matter by means of an electric current from a lcarbon elect-rode or electrodes, and continuing the current until the. desired degree of carburization has been secured, the face' of the plate under treat.'

nient being in the meanwhile screened from air. v

5. The method of incorporating-other'metallic matter into the face of a steel plate and in simultaneously carburizing said face, which consists in applying the said matter to the face of said plate while bothare in' the metallic form, melting .said face and said.

matter by means of an electric current from a. carbon electrode or electrodes, and continuing the current until the desired degree of carburization has been secured, the face i y of the plate under treatment being in the meanwhile screened from air.y

In testimony whereof, I have affixed my signature, in presence of two witnesses.

CLELAND Davis.

Witnessesz.

GRAFTON L.MCG1LL, J. STEPHEN GIUSTA.- 

